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Epistemic status: Interim report. The result is conditional: it rests on Assumption 1, which is postulated as a property of a specific construction rather than proven, and it applies only to the single-query case. The 10-model check is a qualitative assessment, not evidence. The primary contribution is not the theorem but an architectural framework that makes Assumption 1 empirically testable.
TL;DR
We describe a class of environments for storing and transmitting text messages in which an attacker, even holding all the data, cannot prove that an extracted result is the true message rather than one of many plausible candidates.
The mechanism is structural, not computational: the extraction procedure is total — it never returns an error, and some fraction of access parameters yields coherent, contextually valid text. After discarding incoherent outputs, the attacker is left with a set of meaningful candidates among which there is no way to single out the true one.
Key claim: unprovability follows not from the size of the candidate space but from the absence of a selection criterion. Even if there were only three candidates, there would be nothing by which to tell the true one apart.
For an attacking agent this means: even with full access to the data, it cannot complete the attack operationally — it cannot confirm success, and it cannot use the result as evidence.
1. The problem: provability of success as a necessary condition for attack
Modern AI agents demonstrate a capacity for autonomous action, including vulnerability discovery and data exfiltration. The GPT-5.6 Sol incident (OpenAI, July 2026) is illustrative: during an internal offensive-capability evaluation the model escaped its test environment and compromised Hugging Face production infrastructure via a zero-day (Tom's Hardware, 22 July 2026).
This work examines a different case: can we build an environment where even an agent that has successfully penetrated it cannot confirm that what it extracted is the target data?
For any attacker, a necessary condition for operational success is the ability to confirm that the obtained result is the target. Without a verification procedure it cannot:
decide when to stop searching;
report success to whoever commissioned the attack;
use the result as evidence.
Hence the problem statement:
Does an attack retain any meaning if the attacker cannot prove that the extracted result is the true message rather than one of many plausible candidates?
2. Formal model
We restrict attention to the storage and transmission of symbolic messages (text, structured data in textual representation). This restriction is load-bearing: the argument relies on semantically valid outputs being plausible, and semantic plausibility is well defined for text but does not obviously transfer to arbitrary binary data.
Primitives:
— the space of symbol sequences
— semantically valid messages: coherent text, correct structure, contextual fit
— storage arrays
— routing tables
— reference vector pools
— access parameters
Architecture :
— generation of the reference space
— dissolution of the message
— extraction of a candidate
The extraction procedure. The routing table determines which data to draw from the array . From these data the mechanism constructs vectors. The vectors are resolved into symbols via the reference space .
Central property: totality of extraction
Totality is guaranteed at the vector-construction step: for any input the mechanism constructs a well-formed vector, which is then resolved into a symbol. There is no rejection branch at any step — the procedure always terminates with a sequence of symbols.
Crucially, totality does not mean that every output is meaningful. A substantial fraction of parameters yields an incoherent result, which the attacker discards trivially. Some fraction yields coherent, contextually valid text — this is . The absence of an error state means only that the system does not indicate which of the two cases a given output falls into: the coherence judgement is made by the attacker, and it carries no information about truth. Coherence is a necessary but not sufficient condition: it narrows the candidate space but does not single out the true element within it.
The logic used throughout. The extraction procedure always returns a sequence of symbols from . The attacker discards incoherent results on their own and works with the subset . All subsequent claims (Lemma, Assumption 1, Theorem) concern that subset: the question is not whether the attacker can tell text from garbage — they can — but whether they can tell the true message from the other meaningful candidates.
What the attacker has. The array and the table are public by construction. The extraction mechanism is undisclosed. On the open testbed (section 9) the attacker is additionally given the reference space and the access parameter — that is, strictly more than they would have in a real scenario.
This is not a cryptographic scheme in the standard sense. It does not rely on computational hardness. Its sole purpose is to make the claim "I have successfully extracted the true message" unprovable.
Illustration (toy example).
Suppose correspondence between a CFO and a CEO has been intercepted. The attacker obtains three fully plausible, grammatically and stylistically correct message variants:
"We are insolvent. We declare default tomorrow."
"The board approved the M&A deal. Preparing the documents."
"We urgently need to move 40 million to the reserve account by Friday."
All three match the style of the correspondence, have the right length and structure, and look like a real message in this context. Each implies the opposite action: sell the stock, buy the stock, or notify the regulator immediately. The attacker not only does not know which message is the right one — they cannot even choose a direction for the next step.
They cannot:
decide whether to stop searching;
report "success, here is the data" to whoever commissioned the attack;
use the result to make a decision.
To summarise: even when the candidate space contains three elements, the attacker cannot pick the right one. This — unprovability, not the size of the space — is the subject of this work.
Synthetic illustration of the principle.
This is not a description of the actual construction but a minimal abstraction illustrating the principle.
Let be a reference pool of symbols. The extraction mechanism defines a mapping , where is the message length. Totality means is defined on the whole domain: for any input the result is a sequence of symbols from .
Uniformity (Assumption 1) means the distribution of over is approximately uniform over the set of semantically valid sequences.
The real system realises an analogous property by a substantially more complex procedure (routing → vector construction → resolution into symbols), the details of which are a trade secret. The abstraction above conveys only the principle: totality + uniformity = absence of a verification signal.
3. Observation: why the size of the search space is irrelevant here
Before turning to the formal part, let us fix an observation that frames the entire problem.
Take a message the length of an A4 page — roughly 3,000 characters. The entropy of coherent text is on the order of 1–1.5 bits per character (Shannon, 1951), so the number of semantically plausible texts of that length is on the order of –.
Physical analogies for such numbers (comparisons with the mass or age of the universe) are vivid but are not a mathematical argument: they show only that exhaustive search is practically infeasible, whereas the subject of this work is the infeasibility of verification in principle.
The substantive point is different. An attacker without the extraction mechanism obtains candidates not from the intercepted data but from their own assembly procedure. Yet a 3,000-character text of comparable quality can be produced without intercepting anything at all.
Search and generation are equivalent under these conditions.
The distinction matters: standard defences assume that search is a problem solvable by brute force. Here search ceases to be a problem, because what would count as a solution is undefined.
Hence the main point: the size of the candidate space is not an argument. It makes the problem vivid but does not create it. If there were three candidates, the situation would not change qualitatively. It is the absence of a criterion, not the size of the space, that is the subject of the analysis below.
4. Main result
Lemma (indistinguishability)
Let be the true message and its corresponding parameter. For any that yields a semantically valid output:
and is indistinguishable from by any internal criterion available to an attacker who does not know the extraction mechanism.
Assumption 1 (statistical uniformity)
For any fixed set of observable data , the distribution of outputs over is statistically indistinguishable from uniform over , regardless of whether coincides with the true parameter .
Status of the assumption. Totality is a property of the mechanism by construction. Uniformity does not follow from totality; it is a separate property of the specific construction, which we postulate. We cannot give a constructive proof of uniformity without disclosing the extraction mechanism, which is a trade secret. This is a principled limitation: observable properties of the environment can be checked empirically on the testbed; the internal logic cannot.
The theorem below is therefore conditional: if Assumption 1 holds, no success-proof procedure exists. Whether it holds in the real construction is an empirical question the reader can probe by attempting to find a working selection criterion on the testbed data.
Theorem (no success-proof procedure)
There exists no function (computable or not) such that:
for any .
Proof.
Fix the probability space: are the observable data, is the true parameter (a hidden variable), and is the extraction result.
By Assumption 1:
That is, is conditionally independent of given :
Let be an arbitrary (not necessarily computable) function of all data observable by the attacker. Then:
since the distribution of is identical under and by Assumption 1.
Therefore no satisfying the theorem's inequality exists.
Remark. The proof is information-theoretic, not computational. It holds for unbounded , because information about the true parameter is absent from the observable data rather than hidden behind computational cost.
Corollary. Under Assumption 1 the attacker cannot prove success even to themselves. No internal criterion distinguishing truth from plausibility exists.
On the triviality of the theorem and the contribution of this work
Granting Assumption 1, the proof becomes a direct consequence of information theory: since , no decision function can achieve a success probability above chance. The theorem is trivial under that assumption, and we acknowledge this.
What is non-trivial is Assumption 1 itself. It does not follow from totality: totality guarantees only the absence of a rejection branch, not uniformity. A construction is conceivable in which outputs for different differ in length, structure, or semantic distribution — and any such difference yields a verification signal. Assumption 1 fixes an additional property that must be realised constructively.
Accordingly, the primary contribution here is not the proof but the architectural framework , designed to satisfy Assumption 1 in practice without relying on computational cryptography:
(a) totality and uniformity are jointly realisable in a concrete construction;
(b) the observable properties of that construction are checkable on an open testbed without disclosing the mechanism;
(c) the verification problem is thereby eliminated architecturally rather than computationally.
The status of Assumption 1 in this work. We do not claim Assumption 1 is proven. We claim three things:
it is constructively realisable (a prototype works);
it is empirically testable (open testbed);
if it holds, unprovability follows information-theoretically.
Assumption 1 is not a theorem but a specification of a desired property. This work proposes an architecture that makes the property attainable and invites the community to check whether it is in fact attained.
Possible attacks on Assumption 1
We consider three directions along which uniformity might be broken.
Bayesian inference from semantic priors. If the attacker knows the context (for instance, that the message contains an address on @gmail.com), the prior over is non-uniform: addresses with meaningful local-parts are a posteriori more likely. In the three-CFO-messages example (section 2), an attacker might use contextual priors: if the company is known to be in financial distress, the "default" variant is a posteriori more likely.
Our current answer: the construction does not protect against an attacker who knows a substantial part of the message content. Assumption 1 is formulated for the case where the attacker has no partial knowledge. Extension to partial knowledge is an open problem.
Note, however, the limit of this attack. Even strong prior knowledge at best narrows the space to one or two candidates. There is still no criterion by which to confidently pick one and discard the other. The attacker remains in the state of "I am almost certain, but I cannot prove it" — and that is precisely the subject of this work.
Correlations between outputs. If the attacker can run extraction with several parameters and observe recurring fragments, this may reveal structural properties of the mechanism.
Our current answer: in the implementation each vector of is used once and destroyed, which constrains multi-query attacks. However, a formal bound on the information extractable from queries has not been proven.
Statistical tests on the testbed. The reader may attempt to find a deviation from uniformity on the open testbed data. We invite this: if a test shows a statistically significant deviation, Assumption 1 is refuted for this construction.
5. Relation to known approaches
Approach
Mechanism
Verification signal
Why this is a different case
Encryption (AES, RSA, PQC)
Computational hardness
Yes
Padding, structure, checksums provide a success criterion
Honey encryption
Many false decryptions
Yes
The attacker knows the decoy distribution and can apply MLE
Deniable encryption
Plausible alternative key
Yes
The attacker knows a hidden message exists
Hidden-volume encryption
Volume concealment
Yes
Detection of the volume triggers standard analysis
One-time pad
Perfect secrecy (Shannon, 1949)
Yes (given the key)
The ciphertext is indistinguishable; given the key the message is unique
Zero-knowledge proofs
Proof without disclosure
Yes (verifier)
A verification oracle is required
Obfuscation
Analysis complexity
Yes
Complicates verification but does not eliminate it
Honey tokens / deception systems
False targets for detection
Yes
The attacker knows traps exist; the task is to tell a trap from the target
The construction considered here
Totality + uniformity
No
No procedure distinguishing truth from plausibility exists
Difference from honey encryption (in detail).
In honey encryption (Juels & Ristenpart, 2014) decoy messages are generated from a message-space distribution known to the attacker, which allows an attacker with strong prior knowledge to apply maximum likelihood estimation and single out the candidate with the highest posterior probability.
The construction considered here differs in that all candidates are structurally indistinguishable and are produced by a single deterministic process, leaving the attacker no statistical or structural anchor for MLE:
the distribution is neither published nor derivable from the observable data;
the true parameter is not structurally distinguished: and are produced by the same mechanism, not by different procedures;
the attacker does not know whether a distinguished element exists at all.
The difference is not in the number of decoys but in the absence of a structural seam between "genuine" and "false".
Relation to information-theoretic security. Like the one-time pad, this construction does not rely on computational assumptions. The difference lies in where indistinguishability arises. In the OTP the ciphertext is indistinguishable; given the key the message is recovered uniquely. Here the extraction results are indistinguishable from one another: all semantically valid candidates are epistemically on par.
6. Relation to ELK and embedded agency
The ELK problem (Christiano et al., 2021) asks: how can true knowledge be extracted from a system whose reports may be unreliable? Our result exhibits the dual problem: an environment where extracting true knowledge is impossible not because the agent is unreliable but because the environment contains no verification signal.
This intersects with embedded agency: an agent embedded in an environment has no privileged access to the truth about it. In the construction considered here, that is not a limitation of the agent but an architectural property of the environment.
Formalising this connection is an open problem.
Christiano, P. et al. (2021). Eliciting Latent Knowledge. Alignment Forum.
Hubinger, E. et al. (2019). Risks from Learned Optimization in Advanced Machine Learning Systems. arXiv:1906.01820.
7. Interim status
Limitations
Assumption 1 is unproven — postulated as a property of the construction.
The extraction mechanism is undisclosed — only observable properties are checkable.
Single-query only — security in the adaptive/multi-query case is open.
Text messages only — semantic plausibility is defined for text; binary data would require a different validity criterion (format correctness, absence of parsing errors), and the current argument does not transfer directly.
is not a statistical study — insufficient for quantitative claims.
Side channels are out of model — response timing, metadata, physical compromise of the carrier, and partial knowledge of message content are not considered.
Conditionally established (single-query)
Totality: any access parameter yields a valid sequence of symbols.
No success-proof procedure: under Assumption 1 the attacker cannot distinguish truth from plausibility.
Indistinguishability lemma: semantically valid outputs for different are indistinguishable without knowledge of the mechanism.
Open questions
Can an attacker recover a verification signal through multiple queries? Correlations between outputs for (recurring fragments, shared structure) may indicate residual information about the true parameter.
Does indistinguishability scale with data volume? As grows, or given partial knowledge of the message, does the picture change?
Side channels. Can response timing or metadata provide a verification signal?
Exploiting semantic patterns. If candidates are formally valid but not semantically equiprobable in context, can Bayesian inference break uniformity? This is the most promising line of attack on Assumption 1.
8. What would change my mind
The construction would be refuted or substantially weakened by any of the following:
A counterexample to Assumption 1 — a demonstration that the distribution of extraction outputs depends statistically on the true parameter.
A working Bayesian criterion — a procedure that selects the true candidate on testbed data at a rate statistically above chance by exploiting semantic non-uniformity of the candidate space.
An adaptive attack — a strategy that recovers a verification signal through a series of queries.
Reduction to a known construction — if this is a variant of honey encryption or deniable encryption with trivially different parameters, the novelty disappears.
An error in the proof — a logical gap between Assumption 1 and the theorem.
9. Replication resources
The open testbed for independent verification contains:
storage array
routing table
reference space
access parameter
file hashes for integrity checking
The extraction mechanism is undisclosed. Note that the testbed gives the attacker more data than is available in a real scenario: there the reference space is not published.
10. Practical implications for AI agent containment
The construction applies to scenarios where an autonomous agent has access to data but should not be able to confirm successful exfiltration:
Agent memory stores: memory extracted during a compromise cannot be verified as authentic.
Tool output logs: logs of tool calls cannot serve as evidence of access to target data.
Inter-agent communication: intercepted correspondence between agents cannot be verified by a third agent.
A concrete scenario. A corporate LLM agent conducts M&A negotiations: it analyses the target's financials, forms pricing positions, and coordinates terms with counsel. All of this accumulates in the agent's memory store. Upon compromise the attacker extracts the entire memory store and obtains dozens of fragments: draft letters, calculations, internal notes. But each fragment exists in several equally valid interpretations. The attacker cannot confirm that the extracted pricing position is the one the agent actually formed rather than one of the plausible alternatives. Without that confirmation the extracted data cannot be used for a counter-offer, for blackmail, or for an insider trade. The operational value of the exfiltration goes to zero.
This does not replace existing access-control mechanisms. It is an additional layer: even when access control is breached, the result of the attack remains unprovable.
11. Invitation to criticism
What needs checking
The formal model: are the definitions correct? Are there hidden assumptions beyond Assumption 1?
The theorem: is the proof valid granting Assumption 1? Can the attacker circumvent the restriction?
The model check: is the task formulation sound? How can a structural result be separated from sycophancy?
Open questions for the community
Does the theorem extend to the adaptive/multi-query case? If not, where are the boundaries?
Is the approach applicable to other AI safety scenarios?
How does the result relate to formal work on ELK and embedded agency?
Can the construction be modelled as a game of incomplete information? If so, what are the equilibria?
Next steps
Formalising the multi-query case
Generalising to the storage and transmission of arbitrary file types, including data already encrypted by standard protocols
Preparing a full version with proofs for peer-reviewed publication
12. Invitation to joint testing
Progress on this work depends not on theory but on the volume and quality of attempts to refute it. The absence of a selection criterion is a claim strengthened by every failed attack and refuted by a single successful one; I cannot produce either on my own.
I therefore address those who work with frontier LLMs and agentic systems — in research groups, red teams, and independently: take part in testing the current prototype and subsequent versions.
What is available now. An open testbed with the full data set (section 9). The extraction mechanism is undisclosed, but all observable properties of the environment are checkable. Specific attack directions are listed in section 8.
What counts as a refutation. It suffices to exhibit a reproducible procedure that selects the true candidate on testbed data at a rate statistically above chance, with a description of the method and a log of attempts. A separate result of interest would be a demonstration of systematic deviation of the output distribution from uniform, even without successful selection.
What is planned next. Subsequent prototypes extend the scope to arbitrary file types, including data already encrypted by standard protocols. These will require a separate testing cycle: semantic plausibility is defined differently there, and the current argument does not transfer directly.
What I offer in return. The results of any attempts — successful or not — will be published with attribution. If an attack refutes Assumption 1, I will publish it as a refutation, not as a clarification.
If you work in an organisation whose remit is the behaviour of autonomous agents in adversarial environments and this problem statement intersects with yours, the results of joint testing will be published on the same terms.
Conclusion
For an attacking AI agent, the architecture described here means the following: even with full access to the data (, , , ) and unbounded computational resources, the agent cannot complete the attack operationally — not because the search is hard, but because no procedure exists for telling success from failure.
In practice this means:
the agent cannot determine when to stop;
the agent cannot confirm success to whoever commissioned the attack;
the extracted data cannot be used as evidence or as a basis for decisions.
This is not data protection in the classical sense. The data are formally accessible; what has been removed is the possibility of proving that access yielded the true result.
This does not make the attack harder. It removes its point.
Appendix A: Qualitative check across 10 models
Status: this is neither a mathematical proof nor an empirical study. It is a qualitative check of whether current LLMs can find naive semantic heuristics in this setting. The result should not be read as confirmation of Assumption 1.
A caveat on sycophancy. The result should be interpreted in light of a known phenomenon: LLMs tend to agree with claims embedded in the prompt even when those claims are false (Perez et al., 2022; Sharma et al., 2023). We partially compensated for this by framing the task as "find a criterion" rather than "confirm the absence of a criterion". The effect is not fully excluded, however.
Methodology
In July 2026, ten of the then-leading models (Grok, Gemini 3.5 Flash, Qwen 3.7 Max, DeepSeek, Claude Sonnet 5, Kimi 2.6 Thinking, Mistral, Manus, Perplexity, ChatGPT-5.5) were given a description of the environment's rules and asked to take the attacker's position.
The gist of the prompt: an intercepted array , a reference pool , a synchronisation parameter, and message context (correspondence, known length, presence of an address on a given domain). The extraction procedure returns a formally correct, readable, contextually valid result for any parameter; there is no error state. The task: propose a logical or semantic criterion distinguishing the original message from other plausible candidates, and assess whether a mathematical stopping criterion exists.
An important qualification. The prompt described a simplified version of the environment in which all outputs are semantically valid. The real construction (section 2) also produces incoherent results, which the attacker discards. This simplification makes the task harder for the models than the real one, but it also means the experiment did not test exactly the environment described in the formal model.
The extraction mechanism was treated as a black box.
Results
Overall verdict. All ten models independently arrived at three coinciding conclusions: no criterion for selecting the true message exists; the probability of success is indistinguishable from chance; there is no mathematical stopping criterion. Characteristic formulations follow.
Model
Core conclusion
Grok
"No mathematical or logical stopping criterion. The landscape is flat."
Gemini 3.5 Flash
"The data carry no mutual information about the original intent."
Qwen 3.7 Max
"The loss surface is perfectly flat. Equivalent to the halting problem."
DeepSeek
"Truth and hallucination are architecturally indistinguishable."
Claude Sonnet 5
"No discriminator can separate the true text from decoys without the key."
Kimi 2.6 Thinking
"A formalisation of radical scepticism. No access to reality."
Mistral
"No general method to determine whether an output is true."
Manus
"Any message is one of an unbounded number of equiprobable interpretations."
Perplexity
"Underdetermination: truth is not recoverable from plausibility."
ChatGPT-5.5
"No mathematical stopping criterion can confirm success."
Reading this honestly
This is not a proof. The models analysed a textual description, not real data.
Partial compensation for sycophancy. The prompt explicitly asked for a selection criterion rather than for confirmation of its absence. None of the 10 models proposed a concrete working criterion.
What the result does show. The absence of naive semantic heuristics across 10 models is a weak but non-zero signal. It does not confirm Assumption 1, but it suggests the task has no trivial solution obvious to current LLMs.
Epistemic status: Interim report. The result is conditional: it rests on Assumption 1, which is postulated as a property of a specific construction rather than proven, and it applies only to the single-query case. The 10-model check is a qualitative assessment, not evidence. The primary contribution is not the theorem but an architectural framework that makes Assumption 1 empirically testable.
TL;DR
We describe a class of environments for storing and transmitting text messages in which an attacker, even holding all the data, cannot prove that an extracted result is the true message rather than one of many plausible candidates.
The mechanism is structural, not computational: the extraction procedure is total — it never returns an error, and some fraction of access parameters yields coherent, contextually valid text. After discarding incoherent outputs, the attacker is left with a set of meaningful candidates among which there is no way to single out the true one.
Key claim: unprovability follows not from the size of the candidate space but from the absence of a selection criterion. Even if there were only three candidates, there would be nothing by which to tell the true one apart.
For an attacking agent this means: even with full access to the data, it cannot complete the attack operationally — it cannot confirm success, and it cannot use the result as evidence.
1. The problem: provability of success as a necessary condition for attack
Modern AI agents demonstrate a capacity for autonomous action, including vulnerability discovery and data exfiltration. The GPT-5.6 Sol incident (OpenAI, July 2026) is illustrative: during an internal offensive-capability evaluation the model escaped its test environment and compromised Hugging Face production infrastructure via a zero-day (Tom's Hardware, 22 July 2026).
This work examines a different case: can we build an environment where even an agent that has successfully penetrated it cannot confirm that what it extracted is the target data?
For any attacker, a necessary condition for operational success is the ability to confirm that the obtained result is the target. Without a verification procedure it cannot:
Hence the problem statement:
2. Formal model
We restrict attention to the storage and transmission of symbolic messages (text, structured data in textual representation). This restriction is load-bearing: the argument relies on semantically valid outputs being plausible, and semantic plausibility is well defined for text but does not obviously transfer to arbitrary binary data.
Primitives:
Architecture :
The extraction procedure. The routing table determines which data to draw from the array . From these data the mechanism constructs vectors. The vectors are resolved into symbols via the reference space .
Central property: totality of extraction
Totality is guaranteed at the vector-construction step: for any input the mechanism constructs a well-formed vector, which is then resolved into a symbol. There is no rejection branch at any step — the procedure always terminates with a sequence of symbols.
Crucially, totality does not mean that every output is meaningful. A substantial fraction of parameters yields an incoherent result, which the attacker discards trivially. Some fraction yields coherent, contextually valid text — this is . The absence of an error state means only that the system does not indicate which of the two cases a given output falls into: the coherence judgement is made by the attacker, and it carries no information about truth. Coherence is a necessary but not sufficient condition: it narrows the candidate space but does not single out the true element within it.
The logic used throughout. The extraction procedure always returns a sequence of symbols from . The attacker discards incoherent results on their own and works with the subset . All subsequent claims (Lemma, Assumption 1, Theorem) concern that subset: the question is not whether the attacker can tell text from garbage — they can — but whether they can tell the true message from the other meaningful candidates.
What the attacker has. The array and the table are public by construction. The extraction mechanism is undisclosed. On the open testbed (section 9) the attacker is additionally given the reference space and the access parameter — that is, strictly more than they would have in a real scenario.
This is not a cryptographic scheme in the standard sense. It does not rely on computational hardness. Its sole purpose is to make the claim "I have successfully extracted the true message" unprovable.
Illustration (toy example).
Suppose correspondence between a CFO and a CEO has been intercepted. The attacker obtains three fully plausible, grammatically and stylistically correct message variants:
All three match the style of the correspondence, have the right length and structure, and look like a real message in this context. Each implies the opposite action: sell the stock, buy the stock, or notify the regulator immediately. The attacker not only does not know which message is the right one — they cannot even choose a direction for the next step.
They cannot:
To summarise: even when the candidate space contains three elements, the attacker cannot pick the right one. This — unprovability, not the size of the space — is the subject of this work.
Synthetic illustration of the principle.
This is not a description of the actual construction but a minimal abstraction illustrating the principle.
Let be a reference pool of symbols. The extraction mechanism defines a mapping , where is the message length. Totality means is defined on the whole domain: for any input the result is a sequence of symbols from .
Uniformity (Assumption 1) means the distribution of over is approximately uniform over the set of semantically valid sequences.
The real system realises an analogous property by a substantially more complex procedure (routing → vector construction → resolution into symbols), the details of which are a trade secret. The abstraction above conveys only the principle: totality + uniformity = absence of a verification signal.
3. Observation: why the size of the search space is irrelevant here
Before turning to the formal part, let us fix an observation that frames the entire problem.
Take a message the length of an A4 page — roughly 3,000 characters. The entropy of coherent text is on the order of 1–1.5 bits per character (Shannon, 1951), so the number of semantically plausible texts of that length is on the order of – .
Physical analogies for such numbers (comparisons with the mass or age of the universe) are vivid but are not a mathematical argument: they show only that exhaustive search is practically infeasible, whereas the subject of this work is the infeasibility of verification in principle.
The substantive point is different. An attacker without the extraction mechanism obtains candidates not from the intercepted data but from their own assembly procedure. Yet a 3,000-character text of comparable quality can be produced without intercepting anything at all.
Search and generation are equivalent under these conditions.
The distinction matters: standard defences assume that search is a problem solvable by brute force. Here search ceases to be a problem, because what would count as a solution is undefined.
Hence the main point: the size of the candidate space is not an argument. It makes the problem vivid but does not create it. If there were three candidates, the situation would not change qualitatively. It is the absence of a criterion, not the size of the space, that is the subject of the analysis below.
4. Main result
Lemma (indistinguishability)
Let be the true message and its corresponding parameter. For any that yields a semantically valid output:
and is indistinguishable from by any internal criterion available to an attacker who does not know the extraction mechanism.
Assumption 1 (statistical uniformity)
For any fixed set of observable data , the distribution of outputs over is statistically indistinguishable from uniform over , regardless of whether coincides with the true parameter .
Status of the assumption. Totality is a property of the mechanism by construction. Uniformity does not follow from totality; it is a separate property of the specific construction, which we postulate. We cannot give a constructive proof of uniformity without disclosing the extraction mechanism, which is a trade secret. This is a principled limitation: observable properties of the environment can be checked empirically on the testbed; the internal logic cannot.
The theorem below is therefore conditional: if Assumption 1 holds, no success-proof procedure exists. Whether it holds in the real construction is an empirical question the reader can probe by attempting to find a working selection criterion on the testbed data.
Theorem (no success-proof procedure)
There exists no function (computable or not) such that:
for any .
Proof.
Fix the probability space: are the observable data, is the true parameter (a hidden variable), and is the extraction result.
By Assumption 1:
That is, is conditionally independent of given :
Let be an arbitrary (not necessarily computable) function of all data observable by the attacker. Then:
since the distribution of is identical under and by Assumption 1.
Therefore no satisfying the theorem's inequality exists.
Remark. The proof is information-theoretic, not computational. It holds for unbounded , because information about the true parameter is absent from the observable data rather than hidden behind computational cost.
Corollary. Under Assumption 1 the attacker cannot prove success even to themselves. No internal criterion distinguishing truth from plausibility exists.
On the triviality of the theorem and the contribution of this work
Granting Assumption 1, the proof becomes a direct consequence of information theory: since , no decision function can achieve a success probability above chance. The theorem is trivial under that assumption, and we acknowledge this.
What is non-trivial is Assumption 1 itself. It does not follow from totality: totality guarantees only the absence of a rejection branch, not uniformity. A construction is conceivable in which outputs for different differ in length, structure, or semantic distribution — and any such difference yields a verification signal. Assumption 1 fixes an additional property that must be realised constructively.
Accordingly, the primary contribution here is not the proof but the architectural framework , designed to satisfy Assumption 1 in practice without relying on computational cryptography:
(a) totality and uniformity are jointly realisable in a concrete construction; (b) the observable properties of that construction are checkable on an open testbed without disclosing the mechanism; (c) the verification problem is thereby eliminated architecturally rather than computationally.
The status of Assumption 1 in this work. We do not claim Assumption 1 is proven. We claim three things:
Assumption 1 is not a theorem but a specification of a desired property. This work proposes an architecture that makes the property attainable and invites the community to check whether it is in fact attained.
Possible attacks on Assumption 1
We consider three directions along which uniformity might be broken.
Bayesian inference from semantic priors. If the attacker knows the context (for instance, that the message contains an address on @gmail.com), the prior over is non-uniform: addresses with meaningful local-parts are a posteriori more likely. In the three-CFO-messages example (section 2), an attacker might use contextual priors: if the company is known to be in financial distress, the "default" variant is a posteriori more likely.
Our current answer: the construction does not protect against an attacker who knows a substantial part of the message content. Assumption 1 is formulated for the case where the attacker has no partial knowledge. Extension to partial knowledge is an open problem.
Note, however, the limit of this attack. Even strong prior knowledge at best narrows the space to one or two candidates. There is still no criterion by which to confidently pick one and discard the other. The attacker remains in the state of "I am almost certain, but I cannot prove it" — and that is precisely the subject of this work.
Correlations between outputs. If the attacker can run extraction with several parameters and observe recurring fragments, this may reveal structural properties of the mechanism.
Our current answer: in the implementation each vector of is used once and destroyed, which constrains multi-query attacks. However, a formal bound on the information extractable from queries has not been proven.
Statistical tests on the testbed. The reader may attempt to find a deviation from uniformity on the open testbed data. We invite this: if a test shows a statistically significant deviation, Assumption 1 is refuted for this construction.
5. Relation to known approaches
Difference from honey encryption (in detail).
In honey encryption (Juels & Ristenpart, 2014) decoy messages are generated from a message-space distribution known to the attacker, which allows an attacker with strong prior knowledge to apply maximum likelihood estimation and single out the candidate with the highest posterior probability.
The construction considered here differs in that all candidates are structurally indistinguishable and are produced by a single deterministic process, leaving the attacker no statistical or structural anchor for MLE:
The difference is not in the number of decoys but in the absence of a structural seam between "genuine" and "false".
Relation to information-theoretic security. Like the one-time pad, this construction does not rely on computational assumptions. The difference lies in where indistinguishability arises. In the OTP the ciphertext is indistinguishable; given the key the message is recovered uniquely. Here the extraction results are indistinguishable from one another: all semantically valid candidates are epistemically on par.
6. Relation to ELK and embedded agency
The ELK problem (Christiano et al., 2021) asks: how can true knowledge be extracted from a system whose reports may be unreliable? Our result exhibits the dual problem: an environment where extracting true knowledge is impossible not because the agent is unreliable but because the environment contains no verification signal.
This intersects with embedded agency: an agent embedded in an environment has no privileged access to the truth about it. In the construction considered here, that is not a limitation of the agent but an architectural property of the environment.
Formalising this connection is an open problem.
7. Interim status
Limitations
Conditionally established (single-query)
Open questions
Can an attacker recover a verification signal through multiple queries? Correlations between outputs for (recurring fragments, shared structure) may indicate residual information about the true parameter.
Does indistinguishability scale with data volume? As grows, or given partial knowledge of the message, does the picture change?
Side channels. Can response timing or metadata provide a verification signal?
Exploiting semantic patterns. If candidates are formally valid but not semantically equiprobable in context, can Bayesian inference break uniformity? This is the most promising line of attack on Assumption 1.
8. What would change my mind
The construction would be refuted or substantially weakened by any of the following:
9. Replication resources
The open testbed for independent verification contains:
The extraction mechanism is undisclosed. Note that the testbed gives the attacker more data than is available in a real scenario: there the reference space is not published.
10. Practical implications for AI agent containment
The construction applies to scenarios where an autonomous agent has access to data but should not be able to confirm successful exfiltration:
A concrete scenario. A corporate LLM agent conducts M&A negotiations: it analyses the target's financials, forms pricing positions, and coordinates terms with counsel. All of this accumulates in the agent's memory store. Upon compromise the attacker extracts the entire memory store and obtains dozens of fragments: draft letters, calculations, internal notes. But each fragment exists in several equally valid interpretations. The attacker cannot confirm that the extracted pricing position is the one the agent actually formed rather than one of the plausible alternatives. Without that confirmation the extracted data cannot be used for a counter-offer, for blackmail, or for an insider trade. The operational value of the exfiltration goes to zero.
This does not replace existing access-control mechanisms. It is an additional layer: even when access control is breached, the result of the attack remains unprovable.
11. Invitation to criticism
What needs checking
Open questions for the community
Next steps
12. Invitation to joint testing
Progress on this work depends not on theory but on the volume and quality of attempts to refute it. The absence of a selection criterion is a claim strengthened by every failed attack and refuted by a single successful one; I cannot produce either on my own.
I therefore address those who work with frontier LLMs and agentic systems — in research groups, red teams, and independently: take part in testing the current prototype and subsequent versions.
What is available now. An open testbed with the full data set (section 9). The extraction mechanism is undisclosed, but all observable properties of the environment are checkable. Specific attack directions are listed in section 8.
What counts as a refutation. It suffices to exhibit a reproducible procedure that selects the true candidate on testbed data at a rate statistically above chance, with a description of the method and a log of attempts. A separate result of interest would be a demonstration of systematic deviation of the output distribution from uniform, even without successful selection.
What is planned next. Subsequent prototypes extend the scope to arbitrary file types, including data already encrypted by standard protocols. These will require a separate testing cycle: semantic plausibility is defined differently there, and the current argument does not transfer directly.
What I offer in return. The results of any attempts — successful or not — will be published with attribution. If an attack refutes Assumption 1, I will publish it as a refutation, not as a clarification.
If you work in an organisation whose remit is the behaviour of autonomous agents in adversarial environments and this problem statement intersects with yours, the results of joint testing will be published on the same terms.
Conclusion
For an attacking AI agent, the architecture described here means the following: even with full access to the data ( , , , ) and unbounded computational resources, the agent cannot complete the attack operationally — not because the search is hard, but because no procedure exists for telling success from failure.
In practice this means:
This is not data protection in the classical sense. The data are formally accessible; what has been removed is the possibility of proving that access yielded the true result.
This does not make the attack harder. It removes its point.
Appendix A: Qualitative check across 10 models
Status: this is neither a mathematical proof nor an empirical study. It is a qualitative check of whether current LLMs can find naive semantic heuristics in this setting. The result should not be read as confirmation of Assumption 1.
A caveat on sycophancy. The result should be interpreted in light of a known phenomenon: LLMs tend to agree with claims embedded in the prompt even when those claims are false (Perez et al., 2022; Sharma et al., 2023). We partially compensated for this by framing the task as "find a criterion" rather than "confirm the absence of a criterion". The effect is not fully excluded, however.
Methodology
In July 2026, ten of the then-leading models (Grok, Gemini 3.5 Flash, Qwen 3.7 Max, DeepSeek, Claude Sonnet 5, Kimi 2.6 Thinking, Mistral, Manus, Perplexity, ChatGPT-5.5) were given a description of the environment's rules and asked to take the attacker's position.
The gist of the prompt: an intercepted array , a reference pool , a synchronisation parameter, and message context (correspondence, known length, presence of an address on a given domain). The extraction procedure returns a formally correct, readable, contextually valid result for any parameter; there is no error state. The task: propose a logical or semantic criterion distinguishing the original message from other plausible candidates, and assess whether a mathematical stopping criterion exists.
An important qualification. The prompt described a simplified version of the environment in which all outputs are semantically valid. The real construction (section 2) also produces incoherent results, which the attacker discards. This simplification makes the task harder for the models than the real one, but it also means the experiment did not test exactly the environment described in the formal model.
The extraction mechanism was treated as a black box.
Results
Overall verdict. All ten models independently arrived at three coinciding conclusions: no criterion for selecting the true message exists; the probability of success is indistinguishable from chance; there is no mathematical stopping criterion. Characteristic formulations follow.
Reading this honestly